Pneumatic action for piano-players.



" A. E. GOLD SPINK.

PNEUMATIC ACTION FOR PIANOPLAYERS.

APPLICATION, FILED FEB. 4. I919.

1,298,49 1 Pate ntd Mar. 25, 1919.

Inventor. :Erohiald E 4 0m 172%.

@mzmmv UNITED STATES PATENT OFFICE.

ARCHIBALD EATON GOLDSPINK, or KENTISH rovvN, LoNno ENGLAND, ASSIGNOR T0 CHAPPELL & COMPANY, LIMITED, or LONDON, ENGLAND.

PNEUMATIC ACTION FOR PIANO-PLAYERS.

To all whom it may concern:

Be it known that I, AROHIBALD EATON GoLDsPINK, a subject of the King of England, residlng at Kentish Town, in London, England, have invented certain new and useful Improvements in Pneumatic Actions for PianoPlayers, of which the following is a specification.

This invention relates to pneumatic pianoplayer actions of the type wherein a wind trunk or channel board has a seriesof valvecarrying units detachably secured along one side thereof and connected thereto b passages situated atright-angles to the said side of the wind-trunk, and a corresponding number of bellows for the striker-mechanisms are provided located at right-angles to the wind-trunk, each being controlled by its allotted unit.

Heretofore it has been proposed to combine casings containing valves with a bellows to form single detachable units, each valvecasing being securely carried upon its allotted bellows which extend under the windtrunk; in this arrangement the valve-casing and the diaphragm contained therein for operating one of the valves could not be entirely removed together as one unit without also removing the bellows, and the passage for placing the bellows into communication with atmosphere or with the windftrunk was situated in the end of the unit away from the wind-trunk, so that the size of each detachable unit was increased by the space occupied at the end of the unit by this passage. V

This invention has for its object to provide an improved arrangement of the valve-car'- rying units in combination with the bellows and wind-trunk, such that each unit can be readily removed in its entirety from the wind-trunk and its allotted bellows without disturbing these or other parts, and such that the air passages shall be reduced in length and have fewer bends. Such units when defective can be readily scrapped and replaced by others. V

The invention consists in the construction, arrangement and combination of parts described hereinafter and pointed out in the claims.

One embodiment of the invention is illustrated by way of example in the accompanying drawing wherein ig re l is a transverse e t onal eleva- Specifioation of Letters Patent.

Application filed February 4, 1919.

Patented Mar. 25, 1919.

Serial No. 274,944.

'tion showing one form of improved pneumatic piano-player action comprising a wind-trunk and a valve-carrying unit at one side thereof;

Eig. 2 is a top plan view of the unit alone, anc

3 is an end elevation of the unit.

Like reference letters designate like parts in all views.

Referring to the drawing, the unit is divided into two principal parts, an upper part comprising three layers A, A and A of wood or other material, and a lower part comprising the oblon block B also of wood or other material. a recess B in its upper face closed by a flexible diaphragm C of usual constructionl The unit is mounted on a wind-trunk or channel board D in the manner described hereinafter. V

The upper part of the unit is shaped externally to agree with the lower, and is provided in its upper face with a recess E which constitutes the valve-chamber. Its lower face is also recessed at A to register with the recess B in the lower part of the unit, and a passage is pierced in the wall A between the valve-chamber E and the recess A to admit the body of an air-valve F. The air-valve is of the usual double-beat type, having one seating E upon the lower part of the valvechamber and another E which is detachable from the upper face of the valve, is downwardly directed and is secured to the upper face of the upper part of the unit. The valve is guided both at its upper and lower seating. hen the valve is upon its lower seat E the valve-chamber E is open to the atmosphere, and when the valve is upon its upper seat E the chamber E is closed thereto and open to the recess A beneath the valve. A horizontally-situated passage E extends from the valve chamber E 'to the end faceof the upper part of the unit, and a similar passage A extends from the recess A to the same face of the unit. The two parts constituting the unit are united together by screws, the lower face of the one to the upper face of the other, the joint being made airtight, the margin of the flexible diaphragm C being used as packing material.

The wind-trunk D which carries the units is of hollow rectangular section and extends horizontally along the piano-player. 'A'series of units, one foreach note, is bolted along The lower block 13 has one side of the wind-trunk with their pierced sides abutting against it, and their under faces flush with the under surface of the casing D of the wind-trunk. When so united the interior of the wind-trunk communicates with the passage A leading beneath the air valve, and a passage D leading from a bellowsL of the striking-pneumatic and formed in two adjacent sides of'the casing D of the wind-trunk, communicates with the passage E leading to the valve-chamber. tight joint is made by means of packing material P at the contact faces of the unit and the wind-trunk. Bolts G (Figs. 2 and 3) securing the unit to the wind-trunk extend along the sides of the unit and beyond its outer end, grooves being provided in the sides of each unit so that the shank of each bolt lies partly in one unit and partly in the next one which is in contact with it. The washers and nuts upon the bolts therefore bear partly on one unit and partly upon the next adjacent one.

Leading to the recess B beneath the flexible diaphragm C is a passage B pierced in the outer end of the lower part of the unit, and adjacent thereto in the end of the layer A an air-vent H is provided consisting of a pierced metal plug. As clearly shown, a short channel connects the air-vent with the recess B beneath the diaphragm.

A metal plate J '(Fig. 8) having a hemispherical boss J pressed in it is attached by screws to the block B so that the boss I communicates with both the air-vent H and the recess beneath the diaphragm. An upwardlydirected tube K opening into the boss J can be connected by a flexible tube to the trackerbar.

The bellows L of the striking-pneumatic is attached to the underside of the windtrunk D-and extends under, and is in contact with, the lower face of the unit. The member B is not attached to the bellows L by any means.

The action of the above described mechanism is substantially as follows :In Fig. 1 the normal position of the parts are shown in which atmospheric air has free access through the valve chamber E and through the passages E and D to bellows L.

Whenever a perforation on the paper music sheet is brought into registry with one of the ducts in the'tracker board, air will be admitted through the fitting K to the boss J and passage B to the under side of the diaphragm 0. Of course the upper side of the diaphragm is in communication with the exhaust trunk D, and consequently the presence of atmospheric air below the diaphragm G will exert a pressure thereon, driving the same up and moving the valve F up to the upper valve seat E, thus 'shut-' ting out the atmosphere and placing the valve chamber E and the recess A in com- An airmunication. The exhaust trunk D will draw the air from the bellows L through the passage D causing the bellows to actuate 1n the usual way. After the perforation on the music roll has passed the duct the atmospheric air will be shut off from the fitting K, and as soon as the trunk D has exhausted the air from the recess A the atmospheric pressure on the top of the valve F will return this valve to the lower seat E and the apparatus will be then in initial position in readiness for the next actuation. The passage H above the passage E permits the escape of the atmospheric air from the chamber beneath the diaphragm C, and it also furnishes a means of communication between the chamber B and the recess A which permits of establishing and maintaining a balance between these chambers, which is desirable for an efiective action of the diaphragm C.

It will be seen from the above description that each important part of the action is readily accessible for cleaning, adjustment, repairs or renewal, and also that units so constructed are interchangeable.

It will be apparent that various modifications in the arrangement and details herein described can be made without departing from the spirit of the invention as defined in the claims. The material employed in the construction of the unit may be wood, metal, vulcanite or the like as may be required to suit climatic or other conditions.

What I claim as my invention and desire to secure by Letters Patent is 1. In pneumatic piano actions, the com bination of a bellows and a wind trunk having an exhaust space with an opening through one side of the trunk communicating with the, exhaust space and a right angled passage 'communicatingat one end with said bellows and having its other end opening through the side ofthe trunk just above said first mentioned opening, a valve carrying unit removably supported on the bellows at the side of said wind trunk, said unit being composed of three superposed layers, each layer being recessed centrally, the recesses in the layers communicating with each other, the recess in the uppermost layer providing a valve chamber, upper and lower valve seats in said chamber, a double beat valve mounted in said valve chamber and adapted to be alternately moved against said upper and lower seats, said uppermost layer having a passage communicating at one end with said valve chamber and opening at its other end through the side wallofsaid unit, said passage adapted to register with the second mentioned opening in said wind trunk, said lowermost layer having a passage therein communicating with the central recess in said layer at one end and having itsother end opening through the side of said unit, said last named passage adapted to register with the first mentioned opening in said wind trunk, a diaphragm beneath said last mentioned recess and adapted to actuate said valve, and means placing said diaphragm in communication with the ducts of a tracker board, substantially as described.

2. In a pneumatic piano action, the combination with a bellows and a wind trunk, of a valve carrying unit removably supported on said bellows and detachably connected to said wind trunk, said valve carrying unit having a valve chamber therein normally in communication with the atmosphere and constantly in communication with said bellows, said unit having a recess below said valve chamber in communication with the exhaust space of said Wind trunk, a double beat valve adapted to close the communication of the atmosphere with said valve chamber and to place said recess in communication with the bellows, a diaphragm below said valve and recess and adapted to actuate the valve, an air receiving chamber below said diaphragm, a passage leading from said chamber to the outside of said unit, a second passage above said first named passage opening at one end into said recess and at its other end opening at one side of said unit, a plate fitted up against the side of said unit and having a central boss communicating interiorly with both of said passages, and means for placing the interior of said boss in communication with one of the ducts of the tracker board, substantially as described.

In testimony whereof I aflix my signature.

ARG HIBALI) EATON GOLDSPINK.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, I). 0. 

